The present invention relates to a unit for automatically crimping ribbons of flexible flat cable and to a corresponding crimping process.
It is already known practice for very long flat cables to be used to make electrical connections inside a motor vehicle. These flat cables have the advantage of being of small thickness and therefore being able to be slipped behind the interior trim of the vehicle without ruining its appearance. Furthermore, flat cables are lighter in weight than round cables and are less expensive. Of course, just like the round cables (that they replace), they are fitted with connectors at the end of each of their branches.
The crimping of these connectors is a lengthy and tricky operation. Because of the complexity of the bundles of cables, this crimping is often done manually. The branch that is to be crimped is commonly placed in the crimping machine by an operator. This leads to inevitable assembly errors, and very few cable bundles are produced correctly first off. Such a method of performing the crimping entails setting up systematic checks of each bundle, which correspondingly increases the manufacturing time.
The object of the present invention is to create a crimping unit in which the branch to be crimped is placed automatically in the crimping station. The desire is also to guarantee that the branches placed in a crimping station are always the right ones. This makes it possible to reduce the amount of checking to be performed and reduces the time taken to manufacture the ribbon of flat cable.
To this end, the present invention relates to a unit for automatically crimping ribbons of flexible flat cable, said ribbon comprising at least one branch onto which a connector is to be crimped, said unit being characterized in that it comprises:
a guide surface on which the ribbon of flat cable travels,
a number of crimping stations arranged vertically offset plumb with the plane of the guide surface and designed to crimp a connector onto the end of a branch, and
a number of tilting ramps which have a first end even with the plane of the guide surface when they are in the tilted state and a second end even with a crimping station, said ramp being arranged in the opposite direction to the direction of travel of the ribbon, each ramp being designed to tilt toward the guide surface on command so that a predetermined branch of the ribbon follows the ramp it encounters in its path as it travels along and so that it is directed to one of the crimping stations where it receives a connector.
Advantageously, the tilting of the ramp makes it possible to guarantee that only that branch of the ribbon that faces this ramp will be led up to the corresponding crimping station. According to the invention, there is no need to provide a specific means for driving the branch that is to be crimped because the ribbon is rigid enough that the branch for crimping will be driven along at the same time as the ribbon itself.
Of course, the ramps that lead each of the branches for crimping up to a crimping station will have a greater or lesser width according to the configuration of the ribbon of flat cable to be produced. This is because sometimes the branch for crimping contains just two tracks, and sometimes it contains a great many (some ten or so) tracks. In this case, the width of the ramp is tailored each time so that all of the tracks constituting the branch for crimping are directed to the crimping station. In consequence, the ramps according to the invention do not all have the same width. Furthermore, the width of each ramp can be changed according to the ribbon to be produced. To this end, each crimping station has a set of ramps of varying widths. Each time a run of ribbons is to be produced, the appropriate ramps are placed in front of each crimping station.
Advantageously, the tilting of a ramp can be programmed with respect to time. The various connectors can be placed one after another on each of the branches or may be crimped at the same time.
Other objects, features and advantages of the present invention will in any case become apparent from the description which follows, by way of nonlimiting example, with reference to the appended drawings in which: